This invention relates to a termite barrier to prevent the penetration of termites from the ground into a building.
The problem of termites penetrating into buildings from the ground and causing structural damage is old. Further, the damage caused by such termites can be extremely costly to repair. For example, the Formosan termite, which is among the smallest but most destructive of termites, reportedly causes millions of dollars of control and repair costs each year. The Formosan termite is capable of penetrating concrete, tin, copper and hard plastic, so some form of protection is often necessary to prevent damage to structural members exposed to the Formosan termite.
Many approaches have been tried to prevent termites from penetrating into structures.
One approach is to incorporate insecticide impregnated materials into the construction of a building. For example, U.S. Pat. No. 2,899,771 to Burris teaches the placement of a vapor barrier comprising an insecticide impregnated polyethylene film placed between a concrete slab and the ground. Similarly, U.S. Pat. No. 2,952,938 issued to Abrams teaches the use of a resin coated felt layer impregnated with an insecticide that is intended to spread into the ground underneath. Currently, it is common practice to treat the ground beneath a building with chemicals prior to construction in order to poison the soil against termites.
Another approach is to use built-in insecticide stribution systems, such as described in U.S. Pat. No. 2,95,418 issued to Griffin and U.S. Pat. No. 4,625,474 issued to Peacock.
A major disadvantage of termite control methods utilizing insecticide or chemicals is the effect of such pesticides or chemicals on the environment. Due to such concerns, many of the insecticides commonly used have been outlawed or restricted by the Environmental Protection Agency of the United States. Further, insecticide treatment often requires special precautions and specially trained personnel during application of the insecticides, which increases the cost of construction. A still further disadvantage of methods utilizing insecticide is the necessity for retreatment at periodic intervals, which increases costs and increases the risk of exposure to insecticides.
Alternative approaches to preventing penetration of termites that do not utilize insecticides include making structural modifications to buildings. For example, U.S. Pat. No. 2,581,521 issued to Davis describes a method of constructing a building that provides a ventilated passage around the building along the junction of the foundation wall and the superstructure. U.S. Pat. No. 2,352,338 to Muirhead describes the use of precast beams filled with a concrete-based homogenous material. U.S. Pat. No. 2,674,765 to Tennison discloses lock joint configurations for metal termite shields. Finally, U.S. Pat. No. 2,347,776 teaches the combined use of insecticide and structural design in order to confine termite damage to certain predetermined areas which are less costly to replace or repair. However, a disadvantage of these structural inventions is that they increase the complexity of construction.
Thus, there is a need for a termite barrier that does not employ insecticides or other environmentally hazardous substances and yet does not substantially increase the complexity or cost of construction. There is a further need for such a termite barrier that is permanent and does not require retreatment.
It is therefore an object of this invention to provide an effective termite barrier that does not utilize chemical insecticides.
It is a further object of this invention to provide such a termite barrier that may be easily installed and does not substantially increase the cost or complexity of construction.
It is a still further object of this invention to provide such a termite barrier that is permanent.